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TI-2026-44462 Aliases CVE-2026-62239GHSA-w9r7-4gwr-j959

FlashAttention Symlink Attack via tarfile.extractall in hopper/setup.py

Priority MEDIUM 59CWE-59Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
Passive
Attack complexity
Low
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
High · High · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

FlashAttention through 2.8.3.post1, fixed in commit 0816ef1, contains a symlink attack vulnerability in the download_and_copy() function within hopper/setup.py that extracts NVIDIA toolchain archives without validating symlinks or filtering tar members. A local attacker can pre-plant a symlink in the predictable cache directory to redirect extracted binaries to an attacker-chosen location, enabling arbitrary file write with victim privileges during build time.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00164 5th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA
Fix Fixed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Dao-AILabflash-attentionup to 2.8.3.post1—Patch availableCNA
  • flash-attention VendorDao-AILab Affected up to 2.8.3.post1 Fixed in — Patch available CNA

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-62239
  2. 2026-10-03 Alias added: GHSA-w9r7-4gwr-j959

References

Exploit 1

Patch 2

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences